N/A

N/A

N/A

1.What is Corn Protein Peptide?

The corn peptides are a low molecular polypeptide produced by hydrolysis of corn protein. It has many physiological effects such as anti-alcoholism, liver-protection, antihypertension, antitumor, and antioxidation.

2.What is Production of corn protein peptides ?

Enzymatic hydrolysis:Enzymatic hydrolysis is a method to produce the corn protein peptides by hydrolysis of corn protein powder utilizing protease under certain circumstances. This method has many advantages, such as mild reaction condition, strong hydrolysis action specificity, high selectivity, generally without side reaction, and easily controllable reaction process. The enzymes applied in producing corn peptides can be divided into three types：alkaline protease, neutral protease and acidic protease. The optimum conditions for catalytic reactions are generally selected according to the enzyme used. Microbial fermentation :Microbial fermentation is using the specific types of microorganisms in the process of metabolism, relying on their own internal enzyme system to produce peptides form corn protein. The general processes include: strain screening, strain culture, strain identification and optimization, inoculation culture, aerobic fermentation culture, and finished product of corn protein peptides [16]. Comparing to the enzymatic hydrolysis method, the microbial fermentation can reduce the production of bitter peptides while preparing corn peptides, improving their teats and flavor, and lower the production cost. Wu et al[17] obtained a bacillus subtilis which can hydrolyze protein with high ability by casein plate process, and identified its physiological and biochemistry function. After cultivation and optimization, it can ferment corn protein powder to produce corn protein peptides, the result showed its enzyme activity is 1468.7 U/mL, and the corn protein degree of hydrolysis is 9.64%. For now, fewer researches on production of corn protein peptides by microbial fermentation have been done compared to the enzyme hydrolysis method. Although the development prospect is promising, there are still many technical problems to be solved.

3.What are Functional properties of corn protein peptides?

Anti-alcoholism and liver-protection: Drinking is a traditional culture, moderate drinking can promote blood circulation and bring certain health benefits, but excessive drinking will cause drunkenness, severe coma and death. At present, a lot of researches of the anti-alcoholism effect of corn protein peptides have been reported, proving that the corn peptides can promote the ethanol metabolism to achieve the anti-alcoholism effect. Yamaguchi et al[18] studied the impact of corn peptides on the changes of blood ethanol content in rats treated with alcohol intragastric administration, and found that the blood ethanol and acetaldehyde content dropped observably after corn peptides intragastric administration, which indicates the corn peptides can promote ethanol metabolism. Further research shows that corn peptides may have the effect on the reduction of increase in blood ethanol level after alcohol intake by the marked elevation of plasma alanine and leucine to produce oxidized coenzyme I, which speeds up the metabolism of ethanol in the liver. Antihypertension effect: Hypertension is a clinical syndrome characterized by increased systemic arterial blood pressure (systolic blood pressure ≥140 MMHG, diastolic blood pressure ≥90 MMHG) accompanied by functional or organic damage to the heart, brain, kidney and other organs. Abundant studies show that corn protein peptides have the antihypertensive function by inhibiting angiotensin-converting enzymes (ACE), the carboxyl terminus of them with hypotensive activity is proline or aromatic amino acid, and the amino terminus of that is hydrophobic amino acid. Miyoshi et all studied the ACE produced by Thermolysin enzyme hydrolyzing corn protein, and analyzed its chemical structures. They obtained plenty ACE amino acid sequence dominated by tripeptide, most of them were found the carboxyl terminus to be proline such as Leu-Arg-Pro, Leu-Ser-Pro, and Leu-Gln-Pro. Then these peptides were synthesized by a solid phase procedure and verified the inhibitory activity of ACE. Linetal with complex enzymatic method, frozen centrifugation, super nanofiltration separation and purification, low-temperature drying technology for corn protein peptide pilot production, through animal experiments and ACE inhibitory activity test in vitro showed that the activity of corn protein peptides have the good antihypertensive effect, and then using high performance liquid chromatography - electrospray level 4 pole time of flight mass spectrometry technology separation and purification of the lower blood pressure peptide, get the ACE of active peptides principal component for alanine - tyrosine amino acid sequence. Overall, with the increasing number of hypertension patients in world year by year, developing the antihypertensive products with corn peptides as the main ingredient may be an effectual measure to prevent or as adjuvant therapy of hypertension.

4.What is Corn gluten meal?

Corn gluten meal is a major co-product of corn wet milling. Corn gluten meal was hydrolyzed with Alcalase, Flavourzyme, Alcalase+Flavourzyme and Flavourzyme+Alcalase. At the substrate concentration of 10%, corn protein hydrolysate catalyzed by Alcalase had a degree of hydrolysis of 17.83%, which was higher than that by Flavourzyme (3.65%). The hydrolysate catalyzed by Alcalase+Flavourzyme exhibited better antioxidant activities and was further purified. Three novel antioxidant peptides were purified by a series of chromatographic techniques. Sequences of the three peptides were identified as Cys-Ser-Gln-Ala-Pro-Leu-Ala, Tyr-Pro-Lys-Leu-Ala-Pro-Asn-Glu and Tyr-Pro-Gln-Leu-Leu-Pro-Asn-Glu, respectively. Among the three peptides, Cys-Ser-Gln-Ala-Pro-Leu-Ala exhibited good reducing power and excellent scavenging capacities for DPPH radical and superoxide anion radical, with IC50 values of 0.116 and 0.39mg/ml, respectively. The results from our study indicate antioxidant potency of corn protein hydrolysates and peptides separated from corn gluten meal and can provide basic understanding for the application of corn protein hydrolysates as natural antioxidants.